\begin{figure}[htb]
	\centering
	
	\begin{pdfpic}
\psframe[linewidth=0.04,dimen=outer](1.84,1.1784961)(0.02,0.5984961)
\usefont{T1}{ptm}{m}{n}
\rput(0.9014551,0.9034961){$vsplit_0$}
\psframe[linewidth=0.04,dimen=outer](3.64,1.1784961)(1.82,0.5984961)
\usefont{T1}{ptm}{m}{n}
\rput(2.701455,0.9034961){$vsplit_1$}
\psframe[linewidth=0.04,dimen=outer](8.52,1.1784961)(6.3,0.5984961)
\usefont{T1}{ptm}{m}{n}
\rput(7.401455,0.9034961){$vsplit_{m+1}$}
\usefont{T1}{ptm}{m}{n}
\rput(4.027695,1.0984961){\Huge ...}
\psframe[linewidth=0.04,dimen=outer](6.32,1.1784961)(4.5,0.5984961)
\usefont{T1}{ptm}{m}{n}
\rput(5.431455,0.9034961){$vsplit_m$}
\psframe[linewidth=0.04,dimen=outer](11.08,1.1784961)(9.26,0.5984961)
\usefont{T1}{ptm}{m}{n}
\rput(10.141455,0.9034961){$vsplit_n$}
\usefont{T1}{ptm}{m}{n}
\rput(8.827695,1.0984961){\Huge ...}
\psframe[linewidth=0.02,linestyle=dashed,dash=0.16cm 0.16cm,framearc=0.25,dimen=outer](6.32,2.1584961)(0.0,0.07849609)
\usefont{T1}{ptm}{m}{n}
\rput(3.3190331,1.7434961){Already streamed}
\psframe[linewidth=0.02,linestyle=dashed,dash=0.16cm 0.16cm,framearc=0.25,dimen=outer](11.12,2.1584961)(6.32,0.07849609)
\usefont{T1}{ptm}{m}{n}
\rput(8.642813,1.7434961){Not yet streamed}
\psframe[linewidth=0.04,dimen=outer](5.36,-0.7815039)(3.14,-1.361504)
\usefont{T1}{ptm}{m}{n}
\rput(4.141455,-1.0565039){$ecol_{m+1}$}
\psframe[linewidth=0.04,dimen=outer](7.92,-0.7815039)(6.1,-1.361504)
\usefont{T1}{ptm}{m}{n}
\rput(6.881455,-1.0565039){$ecol_n$}
\usefont{T1}{ptm}{m}{n}
\rput(5.6676955,-0.8615039){\Huge ...}
\usefont{T1}{ptm}{m}{n}
\rput(5.7594824,-1.9765038){Rollback (perform $ecol$)}
\psline[linewidth=0.04cm,arrowsize=0.05291667cm 2.0,arrowlength=1.4,arrowinset=0.4]{<-}(4.6,-1.5615039)(7.08,-1.5615039)
\psline[linewidth=0.04cm,arrowsize=0.05291667cm 2.0,arrowlength=1.4,arrowinset=0.4]{<-}(7.16,-0.8015039)(10.16,0.5984961)
\psline[linewidth=0.04cm,arrowsize=0.05291667cm 2.0,arrowlength=1.4,arrowinset=0.4]{<-}(4.24,-0.8015039)(7.24,0.5984961)
\usefont{T1}{ptm}{m}{n}
\rput(6.9076953,0.058496095){\Huge ...}
	\end{pdfpic} 
	\caption{Rollback Mechanism}
	\label{fig:rollbackmechanism}

\end{figure}